In 2010 there were 3 reports of suspected and confirmed cases of wound botulism among people who inject drugs in the United Kingdom. This is less than in 2009 when there were 20 cases reported. However, this is comparable to the previous two years, with 4 cases in reported in 2008 and 3 cases in 2007. Up to the end of 2009 a total of 160 cases had been reported since the first case of wound botulism associated with injecting drug use was reported in March 2000 (data is published in the Shooting Up report).
The symptoms of botulism are caused by a toxin produced by the anaerobic spore forming bacterium Clostridium botulinum. The toxin blocks the release of acetycholine at the neuromuscular junction resulting in a descending flaccid paralysis. Botulism is not spread from one person to another.
There are three main forms of botulism:
The key clinical syndrome produced by botulinum toxin is an afebrile, descending, flaccid paralysis. Patients with botulism typically present with difficulty speaking, seeing and/or swallowing. They may have double vision, blurred vision, drooping eyelids, slurred speech, difficulty swallowing, and muscle weakness. If untreated, paralysis may progress to the arms, legs, trunk and respiratory muscles. There is usually no fever, no loss of sensation and no loss of awareness. There may also be autonomic signs with dry mouth, fixed or dilated pupils, and cardiovascular, gastrointestinal and urinary autonomic dysfunction. If onset is very rapid, there may be no symptoms before sudden respiratory paralysis occurs, which may be fatal. Recovery can take months. Clinicians should suspect botulism in any patient with an afebrile, descending, flaccid paralysis.
Confirmation of the clinical diagnosis is by the demonstration of botulinum toxin in blood samples or, in the case of wound botulism, by the identification of C. botulinum in wound specimens. Routine laboratory tests are not helpful and specimens should therefore be sent immediately to the reference laboratory.
Samples to be taken from acutely ill patients include:
All samples must be kept refrigerated after collection.
All specimens should be sent directly to the reference laboratory with the sender's name and address clearly marked. The reference laboratory should be telephoned prior to sending the sample.
Food Safety Microbiology Laboratory
Centre for Infections
61 Colindale Avenue
Tel: ( 44) 020 8327 6505
Out of office hours, laboratory personnel can be contacted through the HPA Centre for Infections duty doctor on 020 8200 6868.
Specialist advice should be urgently sought from an Infectious Diseases Physician.
Botulinum antitoxin is effective in reducing the severity of symptoms if administered early in the course of the disease. C. botulinum is sensitive to benzyl penicillin and metronidazole. In cases of wound infection, antimicrobial therapy and surgical debridement should reduce the organism load and therefore toxin production, but circulating toxin can only be neutralised by the early administration of antitoxin. Where there is definite clinical suspicion of botulism, treatment with antitoxin should not be delayed for microbiological testing. Antitoxin can be obtained from the Colindale site by contacting the duty doctor on 020 8200 6868.
The risk of death in individuals presenting with wound botulism may be reduced if supportive therapy and antitoxin are provided promptly. Increased awareness amongst clinicians may facilitate prompt diagnosis and treatment.
Wound botulism is thought to occur in people who inject drugs when heroin contaminated with C. botulinum spores is injected into sites that encourage anaerobic conditions. There is no way of telling if a supply of heroin (or other drugs) is contaminated with C. botulinum spores. The following advice may reduce the risk of wound botulism in people who inject drugs:
Information for drug users Botulism infection in those who inject heroin (PDF, 126 KB)
Since food borne botulism constitutes a public health emergency, food must be excluded as a source for all cases of botulism. The HPA has prepared a detailed questionnaire that CCDCs can use to obtain information on clinical presentation, food history and injecting behaviour from all suspected cases of botulism.
Food samples associated with suspected cases of food borne botulism must be obtained as a matter of extreme urgency in order to prevent further cases.
Samples of heroin can be tested by the HPA for the presence of microbial contamination. If the police are in possession of drugs believed to be associated with suspected cases of wound botulism, please contact the HPA FSML on 020 8200 4400 ext 7117 to discuss arrangements for testing.
Clinicians and CCDCs are asked to report any suspected cases of botulism to HPA FSML (020 8200 4400 ext 7117) or to the CfI duty doctor on 020 8200 6868.
Last reviewed: 29 August 2012